Plate heat exchanger

ABSTRACT

Plate heat exchanger includes heat transfer plates each including heat transfer portion with 1st surface and 2nd surface, heat transfer portions stacked in 1st direction, 1st channel for circulating 1st medium in 2nd direction orthogonal to 1st direction formed between opposed 1st surfaces, and 2nd channel for circulating 2nd medium in 2nd direction formed between opposed 2nd surfaces. Each heat transfer portion includes barrier ridges on 1st surface that extend in direction crossing 2nd direction, divides heat transfer portion into divided areas in 2nd direction, and crosses and abuts against ridges of 1st surface of opposed heat transfer portion. Each heat transfer portion includes 2nd flow channel forming valleys on 2nd surface arranged at intervals in 3rd direction orthogonal to both 1st and 2nd directions in each divided area from its one end to its other end in 2nd direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2016-004234, the disclosure of which is incorporated herein by referencein its entirety.

FIELD

The present invention relates to a plate heat exchanger that is used asa condenser and an evaporator.

BACKGROUND

Plate heat exchangers have been conventionally provided. A plate heatexchanger is a type of heat exchanger configured to exchange heatbetween a first fluid medium and a second fluid medium.

The plate heat exchanger includes a plurality of heat transfer plates.Each of the plurality of heat transfer plates includes a heat transferportion. The heat transfer portion has a first surface on which ridgesand valleys are formed, and a second surface that faces an opposite sideto the first surface and on which valleys each serving as the back ofeach corresponding one of the ridges on the first surface and ridgeslocated on the back of the respective valleys on the first surface areformed.

On each of the first surface and the second surface of the heat transferportion, the ridges cross a centerline (hereinafter referred to asvertical centerline) that extends in a second direction orthogonal to afirst direction. The ridges are formed over the entire length of theheat transfer portion in a third direction orthogonal to both the firstdirection and the second direction.

The plurality of heat transfer plates are stacked on each other in thefirst direction. That is, each of the plurality of heat transfer plateshas the first surface of its heat transfer portion opposed to the firstsurface of the heat transfer portion of each adjacent heat transferplate aligned on one side of the first direction. Each of the pluralityof heat transfer plates has the second surface of its heat transferportion opposed to the second surface of the heat transfer portion ofthe adjacent heat transfer plate aligned on the other side of the firstdirection. In this state, the ridges on the heat transfer portions ofeach two adjacent heat transfer plates cross and abut against eachother. With this configuration, the valleys on the heat transferportions form spaces between the heat transfer portions of each twoadjacent heat transfer plates. That is, a first flow channel forcirculating the first fluid medium in the second direction is formedbetween the first surfaces of the heat transfer portions of each twoadjacent heat transfer plates. Also, a second flow channel forcirculating the second fluid medium in the second direction is formedbetween the second surfaces of the heat transfer portions of each twoadjacent heat transfer plates.

In the plate heat exchanger configured as above, the first fluid mediumis circulated through the first flow channels in the second direction.The second fluid medium is circulated through the second flow channelsin the second direction. As a result, the plate heat exchanger enablesheat exchange between the first fluid medium within the first flowchannels and the second fluid medium within the second flow channels,through the heat transfer portions that separate the first flow channelsand the second flow channels (see, for example, Patent Literature 1).

There are some cases where the plate heat exchanger of this type is usedas a condenser that is configured to condense the second fluid mediumwithin the second flow channels through the heat exchange between thefirst fluid medium within the first flow channels and the second fluidmedium within the second flow channels. There are also other cases wherethe plate heat exchanger of this type is used as an evaporator that isconfigured to evaporate the second fluid medium within the second flowchannels through the heat exchange between the first fluid medium withinthe first flow channel and the second fluid medium within the secondflow channels.

However, the conventional plate heat exchanger, if used as the condenseror the evaporator, has a limit in improving heat exchange performancedue to the characteristics of the second fluid medium, which is themedium to be condensed or evaporated.

Specifically, the ridges on each of the heat transfer portions areformed crossing the vertical centerline of the heat transfer portion andextending over the entire length of the heat transfer portion in thethird direction. This configuration causes the ridges of the heat,transfer portion to increase flow resistance of both the first flowchannels and the second flow channels.

Generally, a fluid medium that does not cause phase change (a fluidmedium having single-phase flow) is employed for the first fluid medium.Therefore, increase in the flow resistance in the first flow channelscauses the heat transfer portions to be more likely to be subjected tothermal influences. The increase in the flow resistance in the firstflow channels consequently becomes a factor for improved heat exchangeperformance.

In contrast, a fluid medium that causes phase change (a fluid mediumhaving two-phase flow that contains liquid and gas), such asfluorocarbons, is employed for the second fluid medium. As a result,liquid film of the second fluid medium is formed on each of the secondsurfaces of the heat transfer portions that define the second flowchannels. For the purpose of improving the heat transfer performance,therefore, it is necessary to increase the velocity of the second fluidmedium and disturb flow of the liquid film formed on the second surfaceof the heat transfer portion.

However, the ridges on each the heat transfer portions are formedcrossing the vertical centerline of the heat transfer portion andextending over the entire length of the heat transfer portion in thethird direction. This configuration causes the ridges on the heattransfer portions to block flow of the second fluid medium within thesecond flow channels. That is, the ridges on the second surfaces of theheat transfer portions are formed so as to cross the flow of the secondfluid medium within the second flow channels, and therefore increase theflow resistance of the second fluid medium within the second flowchannels.

Therefore, the conventional plate heat exchanger has a limit inincreasing the velocity of the second fluid medium within the secondflow channels; and thus cannot sufficiently disturb the flow of theliquid film of the second fluid medium formed on the second surface ofthe heat transfer portion.

Hence, the conventional plate heat exchanger has a limit in improvingthe performance for transferring, to the heat transfer portion, heat ofthe second fluid medium that is circulated through the second flowchannels.

CITATION LIST Patent Literature

-   Patent Literature 1: JP 2001-099588 A

SUMMARY Technical Problem

It is therefore an object of the present invention to provide a plateheat exchanger capable of improving performance for transferring, to theheat transfer portions, heat of the second fluid medium that causes thephase change as a result of its heat exchange with the first fluidmedium.

Solution to Problem

The present invention features a plurality of heat transfer plates eachincluding a heat transfer portion having a first surface on which ridgesand valleys are formed, and a second surface that is opposed to thefirst surface and on which valleys being in a front-back relationshipwith the ridges of the first surface and ridges being in a front-backrelationship with the valleys of the first surface are formed, theplurality of heat transfer plates respectively having the heat transferportions stacked on each other in a first direction, wherein the firstsurface of the heat transfer portion of each of the plurality of heattransfer plates is arranged opposed to the first surface of the heattransfer portion of an adjacent heat transfer plate on one side in thefirst direction, and the second surface of the heat transfer portion ofeach of the plurality of heat transfer plates is arranged opposed to thesecond surface of the heat transfer portion of an adjacent heat transferplate on an other side in the first direction, wherein a first flowchannel through which a first fluid medium is circulated in a seconddirection orthogonal to the first direction is formed between the firstsurfaces of the heat transfer portions of each adjacent heat transferplates, and a second flow channel through which a second fluid medium iscirculated in the second direction is formed between the second surfacesof the heat transfer portions of each adjacent heat transfer plates, andwherein the heat transfer portion of at least one of each adjacent heattransfer plates includes: as the ridges formed on the first surface, atleast one barrier ridge that crosses a centerline extending in thesecond direction of the heat transfer portion and is formed over theentire length in a third direction orthogonal to the first direction andthe second direction of the heat transfer portion, and that divides theheat transfer portion into two or more divided areas in the seconddirection, the at least one barrier ridge crossing and abutting againstthe ridges formed on the first surface of the heat transfer portion ofthe opposed heat, transfer plate aligned adjacently and as the valleysformed on the second surface, a plurality of second flow channel formingvalleys constituting part of the second flow channel, the plurality ofsecond flow channel forming valleys being arranged at intervals fromeach other in the third direction in each of the two or more dividedareas from one end to an other end in the second direction of eachcorresponding one of the two or more divided areas.

It is preferable that each of the heat transfer portions of the eachadjacent heat transfer plates include: the at least one barrier ridgeand the second flow channel forming valleys, as the valleys formed onthe first surface, a plurality of first flow channel forming valleysconstituting part of the first flow channel, the plurality of first flowchannel forming valleys being arranged at intervals from each other inthe third direction in each of the two or more divided areas from theone end to the other end in the second direction of each correspondingone of the two or more divided areas, and as the ridges formed on thefirst surface, a plurality of first flow channel side ridges each formedin the third direction between each adjacent first flow channel formingvalleys, the first flow channel side ridges each extending from the oneend to the other end in the second direction of each corresponding oneof the two or more divided areas, and that the first flow channel sideridges in the mutually corresponding divided areas of the adjacent heattransfer plates be arranged with a clearance therebetween.

In this case, a projected amount of the at least one barrier ridge inthe first direction may be set to be larger than a projected amount ofthe first flow channel side ridges in the first direction.

It is preferable that the plurality of first flow channel side ridges inthe mutually corresponding divide areas of the each adjacent heattransfer plates be arranged while being displaced with each other in thethird direction.

It is preferable that each of the heat transfer portions of the eachadjacent heat transfer plates include: the at least one barrier ridgeand the second flow channel forming valleys, and as the ridges formed onthe second surface, a plurality of second flow channel side ridges eachformed in the third direction between each adjacent second flow channelforming valleys, the second flow channel side ridges each extending fromthe one end to the other end of the divided area in the seconddirection, and that top ends of the second flow channel side ridges inthe mutually corresponding divided areas of each adjacent heat transferplates with the second surfaces of the heat transfer portions opposed toeach other be in contact with each other.

It is preferable that each of the heat transfer portions of the eachadjacent heat transfer plates include: the at least one barrier ridgeand the second flow channel forming valleys, and as the ridges formed onthe second surface, a plurality of second flow channel side ridges eachformed in the third direction between each adjacent second flow channelforming valleys, the second flow channel side ridges each extending fromthe one end to the other end in the second direction of eachcorresponding one of the two or more divided areas, and that the secondflow channel side ridges in the mutually corresponding divided areas ofthe each adjacent heat transfer plates with the second surfaces of theheat, transfer portions opposed to each other be arranged with aclearance therebetween.

In this case, the plurality of second flow channel side ridges in themutually corresponding divided areas of the each adjacent heat transferplates may be arranged while being displaced in the third direction.

It is preferable that the at least one barrier ridge include two or moreharrier ridges provided at intervals in the second direction, and thatthe two or more barrier ridges divide each corresponding one of the heattransfer portions into three or more divided areas.

The barrier ridge may include at least one bent ridge portion thatincludes a pair of inclined ridge portions each having a proximal endand a distal end on an opposite side of the proximal end, the pair ofinclined ridge portions being inclined in directions opposite to eachother with respect to the centerline extending in the second directionor a virtual line parallel to the centerline, and having the distal endsthereof connected to each other.

It is preferable that each of the heat transfer portions of the eachadjacent heat transfer plates include the barrier ridge having the bentridge portion, and that the bent ridge portions of the barrier ridges ofthe each adjacent heat transfer plates be bent in directions completelyopposite to each other and includes the inclined ridge portions of thebent ridge portions opposed to each other crossing and abutting againsteach other.

The barrier ridge may extend straightforwardly in the third direction.

Each of the heat transfer portions of the each adjacent heat transferplates may include the barrier ridge extending in the third direction,and the barrier ridges of the each adjacent heat transfer plates may bearranged while being displaced with each other in the second direction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a plate heat exchanger according to oneembodiment of the present invention.

FIG. 2 is an exploded perspective view of the plate heat exchangeraccording to the embodiment, which includes circulation routes of afirst fluid medium and a second fluid medium.

FIG. 3 is a view of a heat transfer plate (first heat transfer plate) ofthe plate heat exchanger according to the embodiment, as seen from itsfirst surface side.

FIG. 4 is a view of the heat transfer plate (first heat transfer plate)of the plate heat exchanger according to the embodiment, as seen fromits second surface side.

FIG. 5 is a view of a heat transfer plate (second heat transfer plate)of the plate heat exchanger according to the embodiment, as seen fromits first surface side.

FIG. 6 is a view of the heat transfer plate (second heat transfer plate)of the plate heat exchanger according to the embodiment, as seen fromits second surface side.

FIG. 7 is a view showing flows of the first fluid medium within a firstflow channel in the plate heat exchanger according to the embodiment.

FIG. 8 is a schematic partial cross-sectional view of the plate heatexchanger according to the embodiment, showing a cross section takenalong ridges on a second flow channel side thereof as seen from a thirddirection with the first flow channels mainly shown.

FIG. 9 is a view showing flows of the second fluid medium within thesecond flow channel in the plate heat exchanger according to theembodiment.

FIG. 10 is a schematic partial cross-sectional view of the plate heatexchanger according to the embodiment, showing a cross section takenalong ridges on a first flow channel side thereof, as seen from thethird direction with the second flow channels mainly shown.

FIG. 11 is a schematic diagram showing a circulation route of the firstfluid medium through the first flow channels and a circulation route ofthe second fluid medium through the second flow channels of the plateheat exchanger according to the embodiment.

FIG. 12 is a view of a heat transfer plate (first heat transfer plate)of a plate heat exchanger according to another embodiment of the presentinvention, as seen from its first surface side.

FIG. 13 is a view of the heat transfer plate (first heat transfer plate)of the plate heat exchanger according to the other embodiment, as seenfrom its second surface side.

FIG. 14 is a view of a heat transfer plate (second heat, transfer plate)of the plate heat exchanger according to the other embodiment, as seenfrom its first surface side.

FIG. 15 is a view of the heat transfer plate (second heat transferplate) of the plate heat exchanger according to the other embodiment, asseen from its second surface side.

FIG. 16 is a schematic diagram showing a circulation route of the firstfluid medium through first flow channels and a circulation route of thesecond fluid medium through second flow channels, of a plate heatexchanger according to still another embodiment of the presentinvention.

FIG. 17 is a schematic diagram showing a circulation route of the firstfluid medium through first flow channels and a circulation route of thesecond fluid medium through second flow channels, of a plate heatexchanger according to still another embodiment of the presentinvention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be describedwith reference to the attached drawings.

As shown in FIG. 1, a plate heat exchanger 1 includes a plurality ofheat transfer plates 2, 3. That is, the plate heat exchanger 1 includesat least three heat transfer plates 2, 3. In this embodiment, the plateheat exchanger 1 includes more than three heat transfer plates 2, 3.Further, in this embodiment, the plurality of heat transfer plates 2, 3include two kinds of heat transfer plates. Accordingly, in the followingdescription, one kind of the heat transfer plate 2 out of the two kindsof heat transfer plates 2, 3 is referred to as a first heat transferplate, and the other kind of the heat transfer plate 3 out of the twokinds of the heat transfer plates 2, 3 is referred to as a second heattransfer plate. However, the first heat transfer plate 2 and the secondheat transfer plate 3 have a common configuration; therefore, for thesake of describing the common configuration, the first heat transferplate 2 and the second heat transfer plate 3 are collectively referredto as the heat transfer plates 2, 3.

First, the common configuration of the first heat transfer plate 2 andthe second heat transfer plate 3 will be described. As shown in FIG. 2,the heat transfer plates 2, 3 respectively include heat transferportions 20, 30 that respectively have first surfaces Sa1, Sb1 andsecond surfaces Sa2, Sb2 facing opposite to the first surfaces Sa1, Sb1,and annular fitting portions 21, 31 that respectively extend from theentire outer peripheral edges of the heat transfer portions 20, 30 whilehaving surfaces extending in a direction intersecting with the surfacesof the heat transfer portions 20, 30.

The heat transfer portions 20, 30 have a thickness in a first direction.Accordingly, the first surfaces Sa1, Sb1 and the second surfaces Sa2,Sb2 of the heat transfer portions 20, 30 are aligned in the firstdirection. As shown in FIG. 3 to FIG. 6, the heat transfer portions 20,30 have an external form (contour) defined by a pair of long sidesextending in a second direction orthogonal to the first direction, and apair of short sides arranged with a distance from each other in thesecond direction while extending in a third direction orthogonal to thefirst direction and the second direction to connect the pair of longsides. That is, the heat, transfer portions 20, 30 have an external formhaving a rectangular shape with the long sides extending in the seconddirection, when seen from the first direction.

Each of the heat transfer portions 20, 30 has one end and the other endon the opposite side to the one end in the second direction. The heattransfer portions 20, 30 respectively have at least two openings 200,201, 202, 203, 300, 301, 302, 303 in each of the one ends and the otherends in the second direction. In this embodiment, the heat transferportions 20, 30 respectively have two openings 200, 203, 300, 303 in theone ends in the second direction, and two openings 201, 202, 301, 302 inthe other ends in the second direction.

The two openings 200, 203, 300, 303 in the one ends in the seconddirection of the heat transfer portions 20, 30 are aligned in the thirddirection. The two openings 201, 202, 301, 302 in the other ends in thesecond direction of the heat transfer portions 20, 30 are aligned in thethird direction.

An area surrounding each of the one openings 200, 300 in the one endsand an area surrounding each of the one openings 201, 301 in the otherends in the second direction of the heat transfer portions 20, 30 arerecessed on the first surfaces Sa1, Sb1 side. Accordingly, an areasurrounding each of the one openings 200, 300 in the one ends and anarea surrounding each of the one openings 201, 301 in the other ends inthe second direction of the heat transfer portions 20, 30 are projectedon the second surfaces Sat, Sb2 side.

A projected amount of the area surrounding each of the openings 200,201, 300, 301 that is projected on the second surfaces Sa2, Sb2 side isset so that the area surrounding each of the openings 200, 201, 300, 301that is projected on the second surfaces Sat, Sb2 side abut against thearea surrounding each corresponding one of the openings 200, 201, 300,301 (the one openings 200, 300 in the one ends and the one openings 201,301 in the other ends) in the heat transfer portions 20, 30 of eachadjacent heat transfer plates 2, 3.

In contrast, an area surrounding each of the other openings 203, 303 inthe one ends and an area surrounding each of the other openings 202, 302in the other ends in the second direction of the heat transfer portions20, 30 are projected on the first surfaces Sa1, Sb1 side. Accordingly,an area surrounding each of the other openings 203, 303 in the one endsand an area surrounding each of the other openings 202, 302 in the otherends in the second direction of the heat transfer portions 20, 30 arerecessed on the second surfaces Sa2, Sb2 side.

A projected amount of the area surrounding each of the openings 202,203, 302, 303 that is projected on the first surfaces Sa1, Sb1 side isset so that the area surrounding each of the openings 202, 203, 302, 303that is projected on the first surfaces Sa1, Sb1 side abut the areasurrounding each corresponding one of the openings 202, 203, 302, 303(the other openings 202, 302 in the one ends and the other openings 203,303 in the other ends) in the heat transfer portions 20, 30 of eachadjacent heat transfer plates 2, 3. In FIG. 3 and FIG. 4, recessed areasout of the areas each surrounding the openings 200, 201, 202, 203, 300,301, 302, 303, and bottom parts of valleys 22, 32, which will bedescribed later, are shown in stippling to allow the relationshipbetween the projected portions and the recessed portions of the firstsurfaces Sa1, Sb1 and the second surfaces Sa2, Sb2 to bedistinguishable.

In this embodiment, the one openings 200, 300 in the one ends and theone openings 201, 301 in the other ends in the second direction of theheat transfer portions 20, 30 are located diagonal to each other, due tothe configuration in which the heat transfer plates 2, 3 are stacked oneach other. The other openings 203, 303 in the one ends and the otheropenings 202, 302 in the other ends in the second direction of the heattransfer portions 20, 30 are also located diagonal to each other.

The valleys 22, 32 and ridges 23, 33 are respectively formed on each ofthe first surfaces Sa1, Sb1 and the second surfaces Sa2, Sb2 of the heattransfer portions 20, 30. Each of the first surfaces Sa1, Sb1 and thesecond surfaces Sa2, Sb2 of the heat, transfer portions 20, 30 has aplurality (a large number) of valleys 22, 32 and a plurality (a largenumber) of ridges 23, 33.

More specifically, each of the heat transfer plates 2, 3 is formed bypress molding of a metal plate. Accordingly the valleys 22, 32 formed onthe first surfaces Sa1, Sb1 of the heat transfer portions 20, 30 are ina front-back relationship with the ridges 23, 33 formed on the secondsurfaces Sa2, Sb2 of the heat transfer portions 20, 30. The ridges 23,33 formed on the first surfaces Sa1, Sb1 of the heat transfer portions20, 30 are in a front-back relationship with the valleys 22, 32 formedon the second surfaces Sa2, Sb2 of the heat, transfer portions 20, 30.That is, the deformation of the metal plate by press molding allows thevalleys 22, 32 formed on the first surfaces Sa1, Sb1 of the heattransfer portions 20, 30 to be formed at positions corresponding to thepositions of the ridges 23, 33 formed on the second surfaces Sa2, Sb2 ofthe heat transfer portions 20, 30. Also, the deformation of the metalplate by press molding allows the ridges 23, 33 formed on the firstsurfaces Sa1, Sb1 of the heat transfer portions 20, 30 to be formed atpositions corresponding to the positions of the valleys 22, 32 formed onthe second surfaces Sa2, Sb2 of the heat, transfer portions 20, 30.

As shown in FIG. 3 and FIG. 5, the heat transfer portion 20, 30includes, as the ridges 23, 33 formed on the first surface Sa1, Sb1, atleast one barrier ridge 230, 330 that crosses a centerline CL extendingin the second direction (hereinafter referred to as vertical centerline)and is formed over the entire length in the third direction, and thatdivides the heat transfer portion 20, 30 into two or more divided areasDa, Db in the second direction, the barrier ridge 230, 330 crossing andabutting against the ridge 23, 33 formed on the first surface Sa1, Sb1of the opposed heat transfer portion 20, 30.

The heat transfer portion 20, 30 includes, as the valleys 22, 32 formedon the first surface Sa1, Sb1, a plurality of first flow channel formingvalleys 220, 320 that constitute part of a first flow channel Ra, theplurality of first flow channel forming valleys 220, 320 being arrangedin each of the two or more divided areas Da, Db from one end to theother end of the divided area Da, Db in the second direction atintervals from each other in the third direction.

The heat transfer portion 20, 30 includes, as the ridges 23, 33 formedon the first surface Sa1, Sb1, a plurality of first flow channel sideridges 231, 331 formed by extending in the second direction between eachadjacent first flow channel forming valleys 220, 320 in the thirddirection.

In this embodiment, two or more barrier ridges 230, 330 are provided atintervals from each other in the second direction. The two or morebarrier ridges 230, 330 divide the heat transfer portion 20, 30 intothree or more divided areas Da, Db.

The barrier ridges 230, 330 include at least one bent ridge portion 232,332. The bent ridge portion 232, 332 includes a pair of inclined ridgeportions 232 a, 232 b, 332 a, 332 b each portion having a proximal endand a distal end on the opposite side of the proximal end, the pair ofinclined ridge portions 232 a, 232 b, 332 a, 332 b being inclined in adirection opposite to each other with respect to the vertical centerlineCL and having the distal ends thereof connected to each other. In thisembodiment, the barrier ridges 230, 330 have one bent ridge portion 232,332.

In this embodiment, the proximal ends of the pair of inclined ridgeportions 232 a, 232 b, 332 a, 332 b that constitute the bent ridgeportion 232, 332 are located on an end edge in the third direction ofthe heat transfer portion 20, 30.

In contrast, the distal ends of the pair of inclined ridge portions 232a, 232 b, 332 a, 332 b are located at the center (on the verticalcenterline CL) in the third direction of the heat transfer portion 20,30. With this, the distal ends of the pair of inclined ridge portions232 a, 232 b, 332 a, 332 b are connected in face-to-Pace relationship.

This configuration allows the barrier ridge 230, 330 itself toconstitute the bent ridge portion 232, 332 in this embodiment. The pairof inclined ridge portions 232 a, 232 b, 332 a, 332 b are symmetricallyarranged with reference to a virtual line that extends in the seconddirection. That is, the pair of inclined ridge portions 232 a, 232 b,332 a, 332 b are inclined in a direction completely opposite to eachother. However, the pair of inclined ridge portions 232 a, 232 b, 332 a,332 b have the same inclination angle with respect, to the verticalcenterline CL extending in the second direction.

A projected amount in the first direction of the barrier ridges 230, 330is set to be larger than that of the first flow channel side ridges 231,331. Accordingly, top ends of the barrier ridges 230, 330 are positionedoutwardly of the top ends of the first flow channel side ridges 231,331. This configuration allows only the barrier ridges 230, 330 out ofthe ridges 23 formed on the first surface Sa1, Sb1 of the heat transferportion 20, 30 to contact the heat transfer portion 20, 30 of theopposed heat transfer plate 2, 3. That is, the first flow channel sideridges 231, 331 are formed to have a lower height than the barrierridges 230, 330 so that they do not contact the opposed heat transferplate 2, 3.

The first flow channel forming valleys 220, 320 and the first flowchannel side ridges 231, 331 formed in each of the divided areas Da, Dbare formed over the entire length in the second direction of the dividedareas Da, Db. Accordingly, at least one end of each of the first flowchannel forming valleys 220, 320 and at least one end of each of thefirst flow channel side ridges 231, 331 are joined to a correspondingone of the barrier ridges 230, 330 that define the divided areas Da, Db.That is, the one ends of the first flow channel forming valleys 220, 320and the first flow channel side ridges 231, 331 respectively are joinedto one of each pair of barrier ridges 230, 330 that define the dividedareas Da, Db. In contrast, the other ends of the first flow channelforming valleys 220, 320 and the first flow channel side ridges 231, 331are joined to the other one of each pair of barrier ridges 230, 330 thatdefine the divided areas Da, Db.

In this embodiment, the plurality of first flow channel forming valleys220, 320 formed in each of the two or more divided areas Da, Db arealigned with each other in the second direction. That is, the first flowchannel forming valleys 220, 320 formed in the two or more divided areasDa, Db correspond in the number and arrangement to each other.Accordingly, the first flow channel side ridges 231, 331 formed in thetwo or more divided areas Da, Db also correspond in the number andarrangement to each other.

As shown in FIG. 4 and FIG. 6, the heat transfer portion 20, 30includes, as the valleys 22, 32 formed on the second surface 5 a 2, Sb2,valleys (hereinafter referred to as back side valleys) 222, 322 formedrespectively on the back sides of the barrier ridges 230, 330 on thefirst surface Sa1, Sb1.

The heat transfer portion 20, 30 include, as the valleys 22, 32 formedon the second surface Sa2, Sb2, a plurality of second flow channelforming valleys 221, 321 that constitute part of a second flow channelRb, the plurality of second flow channel forming valleys 221, 321 beingarranged in each of the two or more divided areas Da, Db from one end tothe other end of the divided area Da, Db in the second direction atintervals from each other in the third direction. Further, the heattransfer portion 20, 30 includes, as the ridges 23, 33 formed on thesecond surface Sa2, Sb2, a plurality of second flow channel side ridges233, 333 formed in the third direction between each adjacent second flowchannel forming valleys 221, 321, the second flow channel side ridges233, 333 each extending from one end to the other end in the seconddirection of the divided area Da, Db.

The back side valleys 222, 322 are formed in the same pattern as thebarrier ridges 230, 330 except that they have a reversed concavo-convexrelationship. On the second surface Sa2, Sb2 of the heat transferportion 20, 30, therefore, a bent valley portion 223, 323 that includesa pair of inclined valley portions 223 a, 223 b, 323 a, 323 b is formed,which is the valley 22, 32 formed on the back side of each pair ofinclined ridge portions 232 a, 232 b, 332 a, 332 b.

In this embodiment, the bent ridge portion 232, 332 (the pair ofinclined ridge portions 232 a, 232 b, 332 a, 332 b) constitutes thebarrier ridge 230, 330. Thus, the bent valley portion 223, 323constitutes each of the entire back side valleys 222, 322 formed on theback side of each of the barrier ridges 230, 330.

The second flow channel forming valleys 221, 321 are the valleys 22, 32formed on the back sides of the first flow channel side ridges 231, 331on the first surface Sa1, Sb1. The second flow channel forming valleys221, 321 are herein described specifically. As described above, thesecond flow channel forming valleys 221, 321 extend from one end to theother end in the second direction of each of the divided areas Da, Db.Here, “extend from one end to the other end in the second direction”means that the second flow channel forming valleys 221, 321 extend fromone end to the other end in the second direction of each of the dividedareas Da, Db at a smaller angle with respect to the virtual lineextending in the second direction than an inclination angle with respectto a virtual line extending in the third direction. In this embodiment,the second flow channel forming valleys 221, 321 extend in the seconddirection. That is, in this embodiment, the second flow channel formingvalleys 221, 321 extend at an angle of 0 degree with respect to thevirtual line extending in the second direction and an angle of 90degrees with respect to the virtual line extending in the thirddirection.

With this configuration, the second flow channel side ridges 233, 333each being formed between each adjacent second flow channel formingvalleys 221, 321 also extend in the second direction. The internalsurfaces that define the second flow channel forming valleys 221, 321are continuous with the external surfaces that define the second flowchannel side ridges 233, 333. With this configuration, the secondsurface Sa2, Sb2 (the divided areas Da, Db) of the heat transfer portion20, 30 has a corrugated shape with projections and recesses aligned inthe third direction.

The second flow channel forming valleys 221, 321 and the second flowchannel side ridges 233, 333 are formed over the entire length in thesecond direction of each of the divided areas Da, Db. The second flowchannel forming valleys 221, 321 are thus continuous with the back sidevalleys 222, 322 formed on the backs of the barrier ridges 230, 330 thatdefine the divided areas Da, Db in which the second flow channel formingvalleys 221, 321 themselves are formed. That is, each of the second flowchannel forming valleys 221, 321 is open to the inside of acorresponding one of the back side valleys 222, 322.

The first heat transfer plates 2 and the second heat transfer plates 3respectively include the heat transfer portions 20, 30 configured asabove. The first heat transfer plates 2 and the second heat transferplates 3 are stacked on each other so that their second surfaces Sa2,Sb2 are opposed to each other while their first surfaces Sa1, Sb1 areopposed to each other. As shown in FIG. 3, therefore, each of the firstheat transfer plates 2 includes the fitting portion 21 projecting on thefirst surface Sa1 side of the heat transfer portion 20. In contrast, asshown in FIG. 6, each of the second heat transfer plates 3 includes thefitting portion 31 projecting on the second surface Sb2 side of the heattransfer portion 30.

Each of the plurality of heat transfer plates 2, 3 (the first heattransfer plates 2 and the second heat, transfer plates 3) has beendescribed as above. The plurality of heat transfer plates 2, 3 (thefirst heat, transfer plates 2 and the second heat transfer plates 3) arestacked on each other in the first direction, as shown in FIG. 2. Inthis embodiment, the first heat transfer plates 2 and the second heattransfer plates 3 are alternately stacked on each other in the firstdirection.

With this configuration, each of the plurality of heat transfer plates2, 3 has the first surface Sa1, Sb1 of its heat transfer portion 20, 30opposed to the first surface Sa1, Sb1 of the heat transfer portion 20,30 of the adjacent heat, transfer plate 2, 3 on one side in the firstdirection. Further, each of the plurality of heat transfer plates 2, 3has the second surface Sa2, Sb2 of its heat transfer portion 20, 30opposed to the second surface Sa2, Sb2 of the heat transfer portion 20,30 of the adjacent heat transfer plate 2, 3 on the other side in thefirst direction.

In this embodiment, as shown in FIG. 7, the plurality of heat transferplates 2, 3 are stacked on each other so that the distal ends of theinclined ridge portions 232 a, 232 b of the barrier ridge(s) 230 (thebent ridge portion(s) 232) of each of the first heat transfer plates 2are located closer to one end in the second direction of the heattransfer portion 20 than the proximal ends thereof, whereas the distalends of the inclined ridge portions 332 a, 332 b of the barrier ridge(s)330 (the bent ridge portion(s) 332) of each of the second heat, transferplates 3 are located closer to the other end in the second direction ofthe heat transfer portion 30 than the proximal ends thereof.

That is, as shown in FIG. 7 and FIG. 8, the first heat transfer plates 2and the second heat transfer plates 3 are stacked alternately on eachother so that one inclined ridge portion 232 a constituting the barrierridge 230 (the bent ridge portion 232) of each of the first heattransfer plates 2 crosses and abuts against one inclined ridge portion332 a constituting the barrier ridge 330 (the bent ridge portion 332) ofeach of the second heat transfer plates 3, and that the other inclinedridge portion 232 b constituting the barrier ridge 230 (the bent ridgeportion 232) of each of the first heat transfer plates 2 crosses andabuts against the other inclined ridge portion 332 b constituting thebarrier ridge 330 (the bent ridge portion 332) of each of the secondheat transfer plates 3.

In this embodiment, as shown in FIG. 2, each of the first heat transferplates 2 and each of the second heat transfer plates 3 are stacked oneach other to form a pair while their back side valleys 222, 322 areopposed to each other. When a plurality of pairs are stacked, everyother pair is turned 180 degrees upside down about a virtual lineextending in the first direction. In this state, the fitting portion 21,31 of one heat transfer plate 2, 3 (the first heat transfer plate 2 orthe second heat transfer plate 3) out of the heat transfer plates 2, 3adjacent to each other in the first direction is fitted onto the fittingportion 21, 31 of the other heat transfer plate 2, 3 (the first heattransfer plate 2 or the second heat transfer plate 3) out of the heattransfer plates 2, 3 adjacent to each other in the first direction.

As shown in FIG. 7, the first flow channel side ridges 231, 331 in themutually corresponding divided areas Da, Db of each adjacent heattransfer plates 2, 3 (the first heat transfer plate 2 and the secondheat transfer plate 3) with their first surfaces Sa1, Sb1 of the heattransfer portions 20, 30 opposed to each other are arranged to overlapeach other when seen from the first direction. As shown in FIG. 8, thefirst flow channel side ridges 231, 331 in the mutually correspondingdivided areas Da, Db of each adjacent heat transfer plates 2, 3 (thefirst heat transfer plate 2 and the second heat transfer plate 3) withtheir first surfaces Sa1, Sb1 on the heat transfer portions 20, 30opposed to each other are located at intervals from each other.

As shown in FIG. 9, the second flow channel side ridges 233, 333 in themutually corresponding divided areas Da, Db of each adjacent heattransfer plates 2, 3 (the first heat transfer plate 2 and the secondheat transfer plate 3) with their second surfaces Sa2, Sb2 of the heattransfer portions 20, 30 opposed to each other are arranged to overlapeach other when seen from the first direction. As shown in FIG. 10, eachadjacent heat transfer plates 2, 3 (the first heat transfer plate 2 andthe second heat transfer plate 3) with the second surfaces Sa2, Sb2 ofthe heat transfer portions 20, 30 opposed to each other have the topends of the second flow channel side ridges 233, 333 in the mutuallycorresponding divided areas Da, Db contacting each other.

With this configuration, as shown in FIG. 2, the first flow channel Rathrough which the first fluid medium A is circulated in the seconddirection orthogonal to the first direction is formed between the firstsurfaces Sa1, Sb1 of the heat transfer portions 20, 30 of each adjacentheat transfer plates 2, 3. The second flow channel Rb through which thesecond fluid medium B is circulated in the second direction is alsoformed between the second surfaces Sa2, Sb2 of the heat transferportions 20, 30 of each adjacent heat transfer plates 2, 3.

Further, as described above, the plurality of heat transfer plates 2, 3are stacked on each other in the first direction so that the openings200, 201, 202, 203, 300, 301, 302, 303 located in the correspondingpositions of the heat transfer portions 20, 30 are lined up in the firstdirection. The areas respectively surrounding the openings 200, 201,202, 203, 300, 301, 302, 303 that are opposed to and projected towardeach other abut each other. This configuration forms a first inflowchannel Pa1 for supplying the first fluid medium A into the first flowchannels Ra, a first outflow channel Pa2 for causing the first fluidmedium A to flow out of the first flow channels Ra, a second inflowchannel Pb1 for supplying the second fluid medium B into the second flowchannels Rb, and a second outflow channel Pb2 for causing the secondfluid medium B to flow out of the second flow channels Rb.

In the plate heat exchanger 1 according to this embodiment, the abuttedportions between the adjacent heat transfer plates 2, 3 are brazedtogether. This configuration allows the plurality of heat transferplates 2, 3 to be integrally (mechanically) connected to each other, andan interface between the opposed surfaces (abutted portions) of theadjacent heat transfer plates 2, 3 to be sealed.

The plate heat exchanger 1 according to this embodiment has beendescribed as above. As shown in FIG. 2, FIG. 7, and FIG. 11, the firstfluid medium A flows from the first inflow channel Pa1 into theplurality of first flow channels Ra. The first fluid medium A iscirculated through each of the first flow channels Ra in the seconddirection, and flows out to the first outflow channel Pa2. In contrast,as shown in FIG. 2, FIG. 9, and FIG. 11, the second fluid medium B flowsfrom the second inflow channel Pb1 into the plurality of second flowchannels Rb. The second fluid medium B is circulated through each of thesecond flow channels Rb in the second direction, and flows out to thesecond outflow channel Pb2.

In this embodiment, as shown in FIG. 7, the first fluid medium A iscirculated through each of the first flow channels Ra with a diagonalline connecting opposing corners of the heat transfer portion 20, 30 asa center of flow. As shown in FIG. 9, in contrast, the second fluidmedium B is circulated through each of the second flow channels Rb withanother diagonal line connecting opposing corners of the heat transferportion 20, 30 as a center of flow, which is different from the diagonalline being the center of the flow of the first fluid medium A.

At this time, the first fluid medium A that is circulated through thefirst flow channels Ra and the second fluid medium B that is circulatedthrough the second flow channels Rb exchange heat via the heat transferplates 2, 3 (the heat transfer portions 20, 30) that separate the firstflow channels Ra and the second flow channels Rb. As a result, thesecond fluid medium B is condensed or evaporated in the course of beingcirculated through the second flow channels Rb in the second direction.

As just described, the plate heat exchanger 1 according to thisembodiment includes: a plurality of heat transfer plates 2, 3 eachincluding a heat transfer portion 20, 30 having a first surface Sa1, Sb1on which ridges 23, 33 and valleys 22, 32 are formed, and a secondsurface Sat, Sb2 that is opposed to the first surface Sa1, Sb1 and onwhich valleys 22, 32 being in a front-back relationship with the ridges23, 33 of the first surface Sa1, Sb1 and ridges 23, 33 being in afront-back relationship with the valleys 22, 32 of the first surfaceSa1, Sb1 are formed, the plurality of heat transfer plates 2, 3respectively having the heat transfer portions 20, 30 stacked on eachother in a first direction, wherein the first surface Sa1, Sb1 of theheat transfer portion 20, 30 of each of the plurality of heat transferplates 2, 3 is arranged opposed to the first surface Sa1, Sb1 of theheat transfer portion 20, 30 of an adjacent heat transfer plate 2, 3 onone side in the first direction, and the second surface Sa2, Sb2 of theheat transfer portion 20, 30 of each of the plurality of heat transferplates 2, 3 is arranged opposed to the second surface Sa2, Sb2 of theheat transfer portion 20, 30 of an adjacent heat transfer plate 2, 3 onan other side in the first direction, wherein a first flow channel Rathrough which a first fluid medium A is circulated in a second directionorthogonal to the first direction is formed between the first surfacesSa1, Sb1 of the heat transfer portions 20, 30 of each adjacent heattransfer plates 2, 3, and a second flow channel Rb through which asecond fluid medium B is circulated in the second direction is formedbetween the second surfaces Sa2, Sb2 of the heat transfer portions 20,30 of each adjacent heat transfer plates 2, 3, and wherein the heattransfer portion 20, 30 of at least one of each adjacent heat transferplates 2, 3 includes: as the ridges 23, 33 formed on the first surfaceSa1, Sb1, at least one barrier ridge 230, 330 that crosses a centerline(vertical centerline) CL extending in the second direction of the heattransfer portion 20, 30 and is formed over the entire length in a thirddirection orthogonal to the first direction and the second direction ofthe heat transfer portion 20, 30, and that divides the heat transferportion 20, 30 into two or more divided areas Da, Db in the seconddirection, the at least one barrier ridge 230, 330 crossing and abuttingagainst the ridges 23, 33 formed on the first surface Sa1, Sb1 of theheat transfer portion 20, 30 of the opposed heat transfer plate 2, 3,and as the valleys 22, 32 formed on the second surface Sa2, Sb2, aplurality of second flow channel forming valleys 221, 321 constitutingpart of the second flow channel Rb, the plurality of second flow channelforming valleys 221, 321 being arranged at intervals from each other inthe third direction in each of the two or more divided areas Da, Db fromone end to an other end in the second direction of each correspondingone of the two or more divided areas Da, Db.

According to the plate heat exchanger 1 configured as above, the barrierridges 230, 330 are projected toward the opposed heat transfer portion20, 30 at intermediate positions of the first flow channel Ra formedbetween the first surfaces Sa1, Sb1 of each adjacent heat transferportions 20, 30 (see FIG. 8). This configuration allows the barrierridges 230, 330 to block circulation of the first fluid medium A throughthe first flow channels Ra to thereby increase the circulatingresistance of the first fluid medium A through the first flow channelsRa. As a result, the first fluid medium A is more likely to thermallyinfluence the heat transfer portions 20, 30, which consequently enhancesheat transfer performance to the second fluid medium B side.

The valleys 22, 32 on the first surface Sa1, Sb1 are in a front-backrelationship with the ridges 23, 33 on the second surface Sa2, Sb2, andthe ridges 23, 33 on the first surface Sa1, Sb1 are in a front-backrelationship with the valleys 22, 32 on the second surface Sa2, Sb2.Accordingly the back side valleys 222, 322 corresponding to the barrierridges 230, 330 are formed on the second surface 5 a 2, Sb2 of the heattransfer portion 20, 30. That is, the back side valleys 222, 322crossing a centerline (vertical centerline) CL that extends in thesecond direction of the heat transfer portion 20, 30 are formed on thesecond surface Sa2, Sb2 of the heat transfer portion 20, 30. Thisconfiguration allows the back side valley(s) 222, 322 to divide the heattransfer portion 20, 30 into two or more divided areas Da, Db on thesecond surface Sa2, Sb2 side.

The plurality of second flow channel forming valleys 221, 321 extendfrom one end to the other end in the second direction of each of thedivided areas Da, Db in which they are located. The plurality of secondflow channel forming valleys 221, 321 are continuous with the back sidevalleys 222, 322 (the valleys 22, 32 corresponding to the barrier ridges230, 330) that define the divided areas Da, Db in which they arelocated. As a result, the second flow channel Rb has nothing that blockscirculation of the second fluid medium B (i.e. that crosses the flowchannel) over the entire length in the second direction.

The second flow channel forming valleys 221, 321 extend from one end tothe other end in the second direction of each of the divided areas Da,Db, Thus, the second flow channel forming valleys 221, 321 extendstraightforwardly in the second direction, or extend while beinginclined in the state where an inclination component (angle) withrespect to a virtual line extending in the second direction is smallerthan an inclination component (angle) with respect to a virtual lineextending in the third direction. This configuration allows the secondflow channel forming valleys 221, 321 to form space (part of the secondflow channel Rb) corresponding to or substantially corresponding to thecirculating direction of the second fluid medium B. Consequently, thecirculating resistance of the second fluid medium B through the secondflow channel Rb can be reduced to increase the velocity of the secondfluid medium B.

As a result, liquid film of the second fluid medium B formed on thesurfaces of the heat, transfer portions 20, 30 is disturbed by theincreased velocity of the second fluid medium B, even if a fluid mediumthat causes phase change (a fluid medium having two-phase flow thatcontains liquid and gas) is employed as the second fluid medium B.

Consequently, the plate heat exchanger 1 configured as above enhancesheat transfer performance of the second fluid medium B circulatedthrough the second flow channels Rb to the heat transfer portions 20, 30(the first fluid medium A side).

In this embodiment, each of the heat transfer portions 20, 30 of theeach adjacent heat transfer plates 2, 3 includes: the at least onebarrier ridge 230, 330 and the second flow channel forming valleys 221,321, as the valleys 22, 32 formed on the first surface Sa1, Sb1, aplurality of first flow channel forming valleys 220, 320 constitutingpart of the first flow channel Ra, the plurality of first flow channelforming valleys 220, 320 being arranged at intervals from each other inthe third direction in each of the two or more divided areas Da, Db fromthe one end to the other end in the second direction of eachcorresponding one of the two or more divided areas Da, Db, and as theridges 23, 33 formed on the first surface Sa1, Sb1, a plurality of firstflow channel side ridges 231, 331 each formed in the third directionbetween each adjacent first flow channel forming valleys 220, 320, thefirst flow channel side ridges 231, 331 each extending from the one endto the other end in the second direction of each corresponding one ofthe two or more divided areas Da, Db, and the first flow channel sideridges 231, 331 in the mutually corresponding divided areas Da, Db ofthe adjacent heat transfer plates 2, 3 are arranged with a clearancetherebetween (see FIG. 8). With this configuration, the inside of eachof the first flow channel Ra is not completely closed but fluidity ofthe first fluid medium A is secured within the first flow channels Rawhile the circulating resistance of the first fluid medium A is alsoapplied to the inside of each of the first flow channels Ra.

Particularly in this embodiment, a projected amount of the at least onebarrier ridge 230, 330 in the first direction is set to be larger than aprojected amount of the first flow channel side ridges 231, 331 in thefirst direction. Accordingly, the barrier ridges 230, 330 having alarger projected amount than the first flow channel side ridges 231, 331cross and abut against the ridges 23, 33 of the opposed heat transferplate 2, 3 (the barrier ridges 230, 330 or the first flow channel sideridges 231, 331). As a result, the first flow channel side ridges 231,331 of the heat transfer portions 20, 30 opposed to each other withinthe first flow channel Ra are not in contact with each other. The firstflow channel Ra is formed over the entire length in the third directionof the heat transfer portions 20, 30. This configuration allows thefirst fluid medium A to spread in the third direction and be circulatedin the second direction through the first flow channel Ra while causingthe circulating resistance therewithin. As a result, the entire areas orthe substantially entire areas of the first surfaces Sa1, Sb1 of theheat transfer portions 20, 30 contribute to heat transfer.

Each of the heat transfer portions 20, 30 of the each adjacent heattransfer plates 2, 3 includes: the at least one barrier ridge 230, 330and the second flow channel forming valleys 221, 321, and as the ridges23, 33 formed on the second surface Sa2, Sb2, a plurality of second flowchannel side ridges 233, 333 each formed in the third direction betweeneach adjacent second flow channel forming valleys 221, 321, the secondflow channel side ridges 233, 333 each extending from the one end to theother end of the divided area Da, Db in the second direction, and topends of the second flow channel side ridges 233, 333 in the mutuallycorresponding divided areas Da, Db of each adjacent heat transfer plates2, 3 with the second surfaces Sa2, Sb2 of the heat transfer portions 20,30 opposed to each other are in contact with each other (see FIG. 10).This configuration prevents the heat transfer portions 20, 30 from beingexpanded even if the fluid pressure of the first fluid medium Acirculated through the first channel Ra acts on the heat transferportions 20, 30. Therefore, the space constituting the second flowchannel Rb is secured to ensure smooth circulation of the second fluidmedium B.

Further, the at least one barrier ridge 230, 330 includes two or morebarrier ridges 230, 330 provided at intervals in the second direction,and the two or more barrier ridges 230, 330 divide each correspondingone of the heat transfer portions 20, 30 into three or more dividedareas Da, Db (see FIG. 7 and FIG. 8). Accordingly, the barrier ridges230, 330 block circulation through the first flow channel Ra at aplurality of (two or more) positions within the first flow channel Ra.This increases the circulating resistance of the first fluid medium Awithin the first flow channel Ra, which consequently enhances heat,transfer performance of the first fluid medium A within the first flowchannel Ra.

The barrier ridge 230, 330 includes at least one bent ridge portion 232,332 that includes a pair of inclined ridge portions 232 a, 232 b, 332 a,332 b each having a proximal end and a distal end on an opposite side ofthe proximal end, the pair of inclined ridge portions 232 a, 232 b, 332a, 332 b being inclined in directions opposite to each other withrespect to the centerline (vertical centerline) CL extending in thesecond direction or a virtual line parallel to the centerline (verticalcenterline) CL, and having the distal ends thereof connected to eachother (see FIG. 3, FIG. 5; and FIG. 7). Accordingly not only do theentire barrier ridges 230, 330 crossing the first flow channel Ra causethe flow resistance to the first fluid medium A, but also the bent ridgeportion 232, 332 (the pair of inclined ridge portions 232 a, 232 b, 332a, 332 b) of the barrier ridges 230, 330 diffuses the first fluid mediumA within the first flow channel Ra. This increases the areascontributing to heat transfer in the heat transfer portions 20, 30, andconsequently enhances heat transfer performance of the first fluidmedium A within the first flow channel. Ra.

Each of the heat transfer portions 20, 30 of the each adjacent heattransfer plates 2, 3 includes the barrier ridge 230, 330 having the bentridge portion 232, 332, and the bent ridge portions 232, 332 of thebarrier ridges 230, 330 of the each adjacent heat transfer plates 2, 3are bent in directions completely opposite to each other and include theinclined ridge portions 232 a, 232 b, 332 a, 332 b of the bent ridgeportions 232, 332 opposed to each other crossing and abutting againsteach other (see FIG. 7). Accordingly, the flow resistance of the firstfluid medium A within the first flow channel Ra is increased and thediffusion effect of the first fluid medium A is also increased. As aresult, heat transfer performance of the first fluid medium A within thefirst flow channel Ra is enhanced.

It is a matter of course that the present invention is not limited tothe aforementioned embodiment, but various modifications can be madewithout departing from the gist of the present invention.

The aforementioned embodiment was described by taking, for example, thecases where, as the adjacent heat transfer plates 2, 3, two kinds ofheat transfer plates 2, 3 (the first heat transfer plate 2 and thesecond heat transfer plate 3) are provided and each of the adjacent heattransfer plates 2, 3 includes the barrier ridges 230, 330 and the secondflow channel forming valleys 221, 331, without limitation thereto. Forexample, one of each adjacent heat transfer plates 2, 3 may include thebarrier ridges 230, 330 and the second flow channel forming valleys 221,321.

The aforementioned embodiment was described by taking, for example, thecase where the second flow channel forming valleys 221, 321 extendstraightforwardly in the second direction, without limitation thereto.For example, the second flow channel forming valleys 221, 321 may beinclined with respect to the virtual line extending in the seconddirection, with the prerequisite that they are continuous with the backside valleys 222, 322. However, in order to increase the velocity of thesecond fluid medium B, the second flow channel forming valleys 221, 321are required to be inclined, satisfying the condition that theinclination component (angle) with respect to the virtual line extendingin the second direction is smaller than the inclination component(angle) with respect to the virtual line extending in the thirddirection.

The aforementioned embodiment was described by taking, for example, thecase where two or more barrier ridges 230, 330 are provided at intervalsfrom each other in the second direction and divide the heat transferportion 20, 30 into three or more divided areas Da, Db, withoutlimitation thereto. For example, one barrier ridge 230, 330 may beprovided on one heat transfer portion 20, 30 and divides the heattransfer portion 20, 30 into two divided areas Da, Db.

The aforementioned embodiment was described by taking, for example, thecase where each adjacent heat transfer plates 2, 3 with the secondsurfaces Sa2, Sb2 of the heat transfer portions 20, 30 opposed to eachother have the top ends of the second flow channel side ridges 233, 333in the mutually corresponding divided areas Da, Db contacting eachother, without limitation thereto. For example, the second flow channelside ridges 233, 333 in the mutually corresponding divided areas Da, Dbof each adjacent heat transfer plates 2, 3 with the second surfaces Sa2,Sb2 of the heat transfer portions 20, 30 opposed to each other may bearranged with a clearance therebetween. This configuration allows thesecond flow channel Rb to be formed continuously over the entire lengthin the second direction and the entire length in the third direction ofthe heat transfer portions 20, 30. Accordingly the circulatingresistance of the second fluid medium B within the second flow channelRb can be reduced to thereby further increase the velocity of the secondfluid medium B.

In this case, the plurality of second flow channel side ridges 233, 333in the mutually corresponding divided areas Da, Db in each adjacent heattransfer plates 2, 3 may be arranged while being displaced (for example,by ¼ pitch) in the third direction. This configuration avoids contactbetween the second flow channel side ridges 233, 333 of the heattransfer portions 20, 30 opposed to each other within the second flowchannel Rb, and hence allows the second flow channel Rb to be continuousover the entire length in the second direction and the entire length inthe third direction of the heat transfer portions 20, 30. As a result,the circulating resistance of the second fluid medium B within thesecond flow channel Rb can be reduced to thereby further increase thevelocity of the second fluid medium B.

The aforementioned embodiment was described by taking, for example, thecase where the projected amount of the barrier ridges 230, 330 is set tobe larger than that of the first flow channel side ridges 231, 331 sothat the first flow channel side ridges 231, 331 are configured not tobe in contact with the opposed heat transfer portion 20, 30, without,limitation thereto. For example, the projected amount of the barrierridges 230, 330 may be set to be the same as the projected amount of thefirst flow channel side ridges 231, 331.

In this case, the plurality of first flow channel side ridges 231, 331in the mutually corresponding divided areas Da, Db in each adjacent heattransfer plates 2, 3 with the first surfaces Sa1, Sb1 of the heattransfer portions 20, 30 opposed to each other may be arranged whilebeing displaced (for example, by ¼ pitch) in the third direction. Thisconfiguration avoids contact between the first flow channel side ridges231, 331 of the heat transfer portions 20, 30 opposed to each otherwithin the first flow channel Ra. The first flow channel Ra extendsthrough the entirety in the second direction of the divide areas Da, Dbof the heat transfer portions 20, 30. However, the flow resistance ofthe first fluid medium A within the first flow channel Ra is increaseddue to the barrier ridges 230, 330 crossing and abutting against eachother, or the barrier ridges 230, 330 crossing and abutting against theridges 23, 33 of the opposed heat, transfer portion 20, 30.

The aforementioned embodiment was described by taking, for example, thecase where the barrier ridge 230, 330 constitutes one bent ridge portion232, 332 including the pair of inclined ridge portions 232 a, 232 b, 332a, 332 b, without limitation thereto. For example, the barrier ridges230, 330 may include a plurality of (two or more) bent ridge portions232, 332. Further, the barrier ridges 230, 330 may be formed into acurved shape when seen from the first direction. Further, the barrierridges 230, 330 may be formed into a corrugated shape with a pluralityof curved portions joined to each other when seen from the firstdirection.

The aforementioned embodiment was described by taking, for example, thecase where the plurality of barrier ridges 230, 330 formed on the firstsurfaces Sa1, Sb1 of the heat, transfer portions 20, 30 are formed intothe same pattern, without limitation thereto. For example, the pluralityof barrier ridges 230, 330 in a different pattern may be formed on thefirst surfaces Sa1, Sb1 of the heat transfer portions 20, 30. Here, thedifferent pattern means that the inclined ridge portions 232 a, 232 b,332 a, 332 b have different inclination angles, the bent ridge portions232, 332 (the inclined ridge portions 232 a, 232 b, 332 a, 332 b) havedifferent inclination directions, or the barrier ridges 230, 330 havedifferent shapes when seen from the first direction, with theprerequisite that the barrier ridges 230, 330 include the bent ridgeportion(s) 232, 332.

The aforementioned embodiment was described by taking, for example, thecase where the barrier ridges 230, 330 including the bent ridge portions232, 332 are formed on each of the heat transfer portions 20, 30 of eachadjacent heat transfer plates 2, 3 with the first surfaces Sa1, Sb1 ofthe heat transfer portions 20, 30 opposed to each other and the bentridge portions 232, 332 of the barrier ridges 230, 330 of each adjacentheat transfer plates 2, 3 are bent in a direction completely opposite toeach other and have the inclined ridge portions 232 a, 232 b, 332 a, 332b of the bent ridge portions 232, 332 opposed to each other crossing andabutting against each other, without limitation thereto. For example, asshown in FIG. 12 to FIG. 15, the barrier ridges 230, 330 and the backside valleys 222, 322 may extend straightforwardly in the thirddirection. This configuration allows the barrier ridges 230, 330 tocross the first flow channel Ra over the entire length of the first flowchannel Ra, which increases the flow resistance of the first fluidmedium A. As a result, the first fluid medium A becomes more likely tocause the heat transfer portions 20, 30 to be subjected to thermalinfluences, which consequently enhances heat transfer performance.

In this case, the configuration may be such that the barrier ridges 230,330 extending in the third direction are formed on each of the heattransfer portions 20, 30 of each adjacent heat transfer plates 2, 3 withthe first surfaces Sa1, Sb1 of the heat transfer portions 20, 30 opposedto each other, and that the barrier ridges 230, 330 of each of theadjacent heat transfer plates 2, 3 are arranged while being displacedfrom each other in the second direction and cross and abut against thefirst flow channel side ridges 231, 331 in each of the divided areas Da,Db of the opposed heat transfer portion 20, 30.

This configuration causes the barrier ridges 230, 330 to blockcirculation through the first flow channel Ra at a plurality of (two ormore) positions within the first flow channel Ra. As a result, thecirculating resistance of the first fluid medium A is increased withinthe first flow channel Ra, which consequently enhances heat transferperformance of the first fluid medium A within the first flow channelRa.

The aforementioned embodiment was described by taking, for example, thecase where the first flow channels Ra are directly communicated with thefirst inflow channel Pa1 and the first outflow channel Pa2 and thesecond flow channels Rb are directly communicated with the second inflowchannel Pb1 and the second outflow channel Pb2, without limitationthereto. For example, as shown in FIG. 16 and FIG. 17, at least twosecond flow channels Rb may be communicated with each other by aconnection flow channel PJ that extends in the first direction at aposition different from the second inflow channel Phi and the secondoutflow channel Pb2 so that the second flow channel Rb located mostupstream of the circulation route including the connection flow channelPJ of the second fluid medium B is connected to the second inflowchannel Pb1 and the second flow channel Rb located most downstream ofthe circulation route including the connection flow channel PJ of thesecond fluid medium B is connected to the second outflow channel Pb2.

More specifically a branch reference space Psi is formed betweenadjacent heat transfer plates 2, 3 at an intermediate position in adirection in which the heat transfer plates 2, 3 are stacked on eachother (i.e. in the first direction). Based on this, the configurationmay be such that one of the second flow channels Rb located on one sideof the branch reference space Ds1 is connected to the branch referencespace Ds1 via the connection flow channel PJ in the first direction, andthat one of the second flow channels Rb located on the other side of thebranch reference space Psi is connected to the branch reference spacePsi via the connection flow channel PJ. This configuration allows thecirculation route of the second fluid medium B to be branched into atleast one first system S1 that is continuous on the one side of thebranch reference space Psi in the first direction and at least onesecond system S2 that is continuous on the other side of the branchreference space Psi in the first direction.

In the case where the circulation route of the second fluid medium Bincludes the first system S1 and the second system S2, each of the firstsystem S1 and the second system S2 may have a branch reference space(branch reference space on the downstream side) Ds2 formed betweenadjacent heat transfer plates 2, 3 that define at least one second flowchannel Rb located at an intermediate position in the first directionand directly or indirectly connected to the branch reference space Ds1upstream thereof via the connection flow channel PJ. In this case, thesecond flow channel Rb located on one side of the branch reference spaceDs2 in the first direction is connected to the branch reference spaceDs2 on the downstream side via the connection flow channel PJ, and thesecond flow channel Rb located on the other side of the branch referencespace Ds2 in the first direction is connected to the branch referencespace Ds2 on the downstream side via the connection flow channel PJ.This configuration allows the circulation route of the second fluidmedium B in each of the first system S1 and the second system S2 to befurther branched into at least two systems S1 a, S1 b, S2 a, S2 b, andthe second flow channel Rb located most downstream of each of thesystems S1 a, S1 b, S2 a, S2 b to be connected to the second outflowchannel Pb2. Note that there may be one or more second flow channels Rblocated most downstream of each of the systems S1 a, S1 b, S2 a, S2 b(the second flow channels Rb connected to the second outflow channelPb2).

REFERENCE SIGNS LIST

-   1: Plate heat exchanger-   2: First heat transfer plate (heat transfer plate)-   3: Second heat transfer plate (heat transfer plate)-   20, 30: Heat transfer portion-   21, 31: Fitting portion-   22, 32: Valley-   23, 33: Ridge-   200, 201, 202, 203, 300, 301, 302, 303: Opening-   220, 320: First flow channel forming valley-   221, 321: Second flow channel forming valley-   222, 322: Back side valley-   223, 323: Bent valley portion-   223 a, 223 b, 323 a, 323 b: Inclined valley portion-   230, 330: Barrier ridge-   231, 331: First flow channel side ridge-   232, 332: Bent ridge portion-   232 a, 232 b, 332 a, 332 b: Inclined ridge portion-   233, 333: Second flow channel side ridge-   A: First fluid medium.-   B: Second fluid medium-   CL: Vertical centerline (centerline)-   Da, Db: Divided area-   Ds1: Branch reference space-   Ds2: Branch reference space-   Pa1: First inflow channel-   Pa2: First outflow channel-   Pb1: Second inflow channel-   Pb2: Second outflow channel-   PJ: Connection flow channel-   Ra: First flow channel-   Rb: Second flow channel-   S1: First system-   S2: Second system-   S1 a, S1 b, S2 a, S2 b: System-   Sa1, Sb1: First surface-   Sa2, Sb2: Second surface

1. A plate heat exchanger, comprising: a plurality of heat transferplates each including a heat transfer portion having a first surface onwhich ridges and valleys are formed, and a second surface that isopposed to the first surface and on which valleys being in a front-backrelationship with the ridges of the first surface and ridges being in afront-back relationship with the valleys of the first surface areformed, the plurality of heat transfer plates respectively having theheat transfer portions stacked on each other in a first direction,wherein the first surface of the heat transfer portion of each of theplurality of heat transfer plates is arranged opposed to the firstsurface of the heat transfer portion of an adjacent heat transfer plateon one side in the first direction, and the second surface of the heattransfer portion of each of the plurality of heat transfer plates isarranged opposed to the second surface of the heat transfer portion ofan adjacent heat transfer plate on an other side in the first direction,wherein a first flow channel through which a first fluid medium iscirculated in a second direction orthogonal to the first direction isformed between the first surfaces of the heat transfer portions of eachadjacent heat transfer plates, and a second flow channel through which asecond fluid medium is circulated in the second direction is formedbetween the second surfaces of the heat transfer portions of eachadjacent heat transfer plates, and wherein the heat transfer portion ofat least one of each adjacent heat transfer plates comprises: as theridges formed on the first surface, at least one barrier ridge thatcrosses a centerline extending in the second direction of the heattransfer portion and is formed over the entire length in a thirddirection orthogonal to the first direction and the second direction ofthe heat transfer portion, and that divides the heat transfer portioninto two or more divided areas in the second direction, the at least onebarrier ridge crossing and abutting against the ridges formed on thefirst surface of the heat transfer portion of the opposed heat transferplate aligned adjacently, and as the valleys formed on the secondsurface, a plurality of second flow channel forming valleys constitutingpart of the second flow channel, the plurality of second flow channelforming valleys being arranged at intervals from each other in the thirddirection in each of the two or more divided areas from one end to another end in the second direction of each corresponding one of the twoor more divided areas.
 2. The plate heat exchanger according to claim 1,wherein each of the heat transfer portions of the each adjacent heattransfer plates comprises: the at least one barrier ridge and the secondflow channel forming valleys, as the valleys formed on the firstsurface, a plurality of first flow channel forming valleys constitutingpart of the first flow channel, the plurality of first flow channelforming valleys being arranged at intervals from each other in the thirddirection in each of the two or more divided areas from the one end tothe other end in the second direction of each corresponding one of thetwo or more divided areas, and as the ridges formed on the firstsurface, a plurality of first flow channel side ridges each formed inthe third direction between each adjacent first flow channel formingvalleys, the first flow channel side ridges each extending from the oneend to the other end in the second direction of each corresponding oneof the two or more divided areas, and wherein the first flow channelside ridges in the mutually corresponding divided areas of the adjacentheat transfer plates are arranged with a clearance therebetween.
 3. Theplate heat exchanger according to claim 2, wherein a projected amount ofthe at least one barrier ridge in the first direction is set to belarger than a projected amount of the first flow channel side ridges inthe first direction.
 4. The plate heat exchanger according to claim 2,wherein the plurality of first flow channel side ridges in the mutuallycorresponding divide areas of the each adjacent heat transfer plates arearranged while being displaced with each other in the third direction.5. The plate heat exchanger according to claim 1, wherein each of theheat transfer portions of the each adjacent heat transfer platescomprises: the at least one barrier ridge and the second flow channelforming valleys, and as the ridges formed on the second surface, aplurality of second flow channel side ridges each formed in the thirddirection between each adjacent second flow channel forming valleys, thesecond flow channel side ridges each extending from the one end to theother end of the divided area in the second direction, and top ends ofthe second flow channel side ridges in the mutually correspondingdivided areas of each adjacent heat transfer plates with the secondsurfaces of the heat transfer portions opposed to each other are incontact with each other.
 6. The plate heat exchanger according to claim1, wherein each of the heat transfer portions of the each adjacent heattransfer plates comprises: the at least one barrier ridge and the secondflow channel forming valleys, and as the ridges formed on the secondsurface, a plurality of second flow channel side ridges each formed inthe third direction between each adjacent second flow channel formingvalleys, the second flow channel side ridges each extending from the oneend to the other end in the second direction of each corresponding oneof the two or more divided areas, and the second flow channel sideridges in the mutually corresponding divided areas of the each adjacentheat transfer plates with the second surfaces of the heat transferportions opposed to each other are arranged with a clearancetherebetween.
 7. The plate heat exchanger according to claim 6, whereinthe plurality of second flow channel side ridges in the mutuallycorresponding divided areas of the each adjacent heat transfer platesare arranged while being displaced in the third direction.
 8. The plateheat exchanger according to claim 1, wherein the at least one barrierridge includes two or more barrier ridges provided at intervals in thesecond direction, and the two or more barrier ridges divide eachcorresponding one of the heat transfer portions into three or moredivided areas.
 9. The plate heat exchanger according to claim 1, whereinthe barrier ridge comprises at least one bent ridge portion thatcomprises a pair of inclined ridge portions each having a proximal endand a distal end on an opposite side of the proximal end, the pair ofinclined ridge portions being inclined in directions opposite to eachother with respect to the centerline extending in the second directionor a virtual line parallel to the centerline, and having the distal endsthereof connected to each other.
 10. The plate heat exchanger accordingto claim 9, wherein each of the heat transfer portions of the eachadjacent heat transfer plates includes the barrier ridge having the bentridge portion, and the bent ridge portions of the barrier ridges of theeach adjacent heat transfer plates are bent in directions completelyopposite to each other and comprise the inclined ridge portions of thebent ridge portions opposed to each other crossing and abutting againsteach other.
 11. The plate heat exchanger according to claim 1, whereinthe barrier ridge extends straightforwardly in the third direction. 12.The plate heat exchanger according to claim 11, wherein each of the heattransfer portions of the each adjacent heat transfer plates includes thebarrier ridge extending in the third direction, and the barrier ridgesof the each adjacent heat transfer plates are arranged while beingdisplaced with each other in the second direction.